反投影构造二维旋转不变小波用于边缘检测

通过数值反投影的方法,从一维小波得到二维小波的离散形式。该二维小波具有旋转不变的特点,所以图像在每个方向上的边缘都能得到有效的检测。在非极大值抑制中,同时使用这种二维旋转不变小波与二维Mallat方向小波,阈值的设置更加合理,从而使边缘的定位更加准确。试验表明这种二维旋转不变小波结合Mallat方向小波有更好的检测效果。     

Multipartite concurrence for X states under decoherence

In this paper, the dynamics evolution of multipartite entanglement for each qubit interacting with a local decoherence channel, such as phase damping, phase flip, bit flip and bit-phase flip channel, is investigated. It is shown that the initial concurrence monotonously decreases much faster with the number of qubit increases and there exists entanglement sudden death (ESD) only for the bit flip channel and bit-phase flip channels. Meanwhile, the time of ESD decreases with the increases of the number of qubit in the multipartite system.     

Multipartite quantum systems and symplectic toric manifolds

In this paper we study the geometrical structures of multi-qubit states based on symplectic toric manifolds. After a short review of symplectic toric manifolds, we discuss the space of a single quantum state in terms of these manifolds. We also investigate entangled multipartite states based on moment map and Delzant’s construction of toric manifolds and algebraic toric varieties.     

Invariant approximations of the minimal robust positively Invariant set

This note provides results on approximating the minimal robust positively invariant (mRPI) set (also known as the 0-reachable set) of an asymptotically stable discrete-time linear time-invariant system. It is assumed that the disturbance is bounded, persistent and acts additively on the state and that the constraints on the disturbance are polyhedral. Results are given that allow for the computation of a robust positively invariant, outer approximation of the mRPI set. Conditions are also given that allow one to a priori specify the accuracy of this approximation.     

基于多部访问结构的理想的秘密共享方案

在多部访问结构中,参与者集合被分为m个子集,同一子集中的参与者在系统中起到相同的作用。文章介绍了多部访问结构的概念,构造了一种三部访问结构,并通过向量空间构造法从理论上证明了该三部访问结构是理想的访问结构。通过该文提出的方法,可以很容易地将三部访问结构的结论推广到多部访问结构。     

Efficient Invariant Representations

Invariant representations are frequently used in computer vision algorithms to eliminate the effect of an unknown transformation of the data. These representations, however, depend on the order in which the features are considered in the computations. We introduce the class of projective/permutation p²-invariants which are insensitive to the labeling of the feature set. A general method to compute the p²-invariant of a point set (or of its dual) in the n-dimensional projective space is given. The one-to-one mapping between n + 3 points and the components of their p²-invariant representation makes it possible to design correspondence algorithms with superior tolerance to positional errors. An algorithm for coplanar points in projective correspondence is described as an application, and its performance is investigated. The use of p²-invariants as an indexing tool in object recognition systems may also be of interest.     

Invariant fuzzy implications

Paper deals with fuzzy implications invariant with respect to the family of all increasing bijections in [0,1]. We describe the family of all such fuzzy implications which forms a distributive lattice. The classical implication axioms are verified in this family.     

Invariant time-series factorization

Time-series analysis is an important domain of machine learning and a plethora of methods have been developed for the task. This paper proposes a new representation of time series, which in contrast to existing approaches, decomposes a time-series dataset into latent patterns and membership weights of local segments to those patterns. The process is formalized as a constrained objective function and a tailored stochastic coordinate descent optimization is applied. The time-series are projected to a new feature representation consisting of the sums of the membership weights, which captures frequencies of local patterns. Features from various sliding window sizes are concatenated in order to encapsulate the interaction of patterns from different sizes. The derived representation offers a set of features that boosts classification accuracy. Finally, a large-scale experimental comparison against 11 baselines over 43 real life datasets, indicates that the proposed method achieves state-of-the-art prediction accuracy results.     

Multipartite electronic entanglement purification using quantum-dot spin and microcavity system

This paper presents an entanglement purification protocol of multipartite electronic spin entangled state resorting to quantum-dot (QD) spin and micro cavity coupled system. The QD and microcavity coupling system is used to construct parity check detectors which provides a novel experimental platform of quantum information processing with photon and solid qubit. In this proposed protocol, the mixed multi-electron entangled state ensemble can be purified efficiently.     

Numerically Invariant Signature Curves

Corrected versions of the numerically invariant expressions for the affine and Euclidean signature of a planar curve introduced by Calabi et al. in (Int. J. Comput. Vision, 26: 107–135, 1998) are presented. The new formulas are valid for fine but otherwise arbitrary partitions of the curve. We also give numerically invariant expressions for the four differential invariants parameterizing the three dimensional version of the Euclidean signature curve, namely the curvature, the torsion and their derivatives with respect to arc length.     

Shape-based Invariant Texture Indexing

This paper introduces a new texture analysis scheme, which is invariant to local geometric and radiometric changes. The proposed methodology relies on the topographic map of images, obtained from the connected components of level sets. This morphological tool, providing a multi-scale and contrast-invariant representation of images, is shown to be well suited to texture analysis. We first make use of invariant moments to extract geometrical information from the topographic map. This yields features that are invariant to local similarities or local affine transformations. These features are invariant to any local contrast change. We then relax this invariance by computing additional features that are invariant to local affine contrast changes and investigate the resulting analysis scheme by performing classification and retrieval experiments on three texture databases. The obtained experimental results outperform the current state of the art in locally invariant texture analysis.     

基于时间序列与多部图的演化聚类动态分析

提出演化聚类动态分析法,使用图论理论,将时间序列数据集通过聚类分析表示为一个多部图。该图实观了对时间序列之间的群体级和个体级动态交互行为的捕捉和建模,不但能够追踪各个时间序列的来龙去脉,而且能对捕获的交互行为加以利用。     

Propagators,Tomograms, Wavelets and Quasidistributions for Multipartite Quantum Systems

Integral transforms of analytic signal and quantum-system states like wavelets, tomograms, Ville-Wigner and other quasidistributions are constructed for systems with several degrees of freedom. Mutual relations of the integral transforms are presented. Quantum propagator is interpreted as the kernel of the integral transform. An example of the integral transforms with generic Gaussian kernels is studied. The fractional Fourier transform is discussed.     

Training Invariant Support Vector Machines

Practical experience has shown that in order to obtain the best possible performance, prior knowledge about invariances of a classification problem at hand ought to be incorporated into the training procedure. We describe and review all known methods for doing so in support vector machines, provide experimental results, and discuss their respective merits. One of the significant new results reported in this work is our recent achievement of the lowest reported test error on the well-known MNIST digit recognition benchmark task, with SVM training times that are also significantly faster than previous SVM methods.     

Analytical Design of Invariant Controllers

Constructive conditions for the invariance of linear systems are derived from pencils of reduced-order matrices and applied to develop a method of design of invariant controllers. Examples illustrating the application of the analytical design method are given.     

横切侵入性和横切不变性

由于面向方面语言的不知觉性和多量化特点,模块分析和模块推理比传统方法学更加困难.为了解决面向方面语言的横切安全和横切质量问题,使用前提条件和后验条件约束横切模块和被横切模块,然而在横切过程中寻找前提条件和后验条件的失败原因十分微妙和复杂.为了分析一个横切关注点的行为影响,程序员需要考虑方面本身和这个方面影响的系统其他部分.当几个方面编织在同一个切入点,危险干扰分析变得更加复杂.类似面向对象语言中的行为子类型概念,引入横切不变性概念.为了检查由于破坏横切不变性引起的行为错误和其他4种简单行为错误,基于软件行为契约提出一个横切不变性检测算法.为了形式化这个算法,提出Crosscutting Contract演算和一组契约求解规则,并通过定义和证明契约完备性来保证契约求解过程的正确性.还使用一个例子说明如何使用这些契约求解规则检测和分析行为错误.     

Invariant analysis of CP violation

The invariant formulation of CP violation involves the generation of sets of invariant constraints for CP conservation, the manipulation of their expressions and the identification of complete and minimal subsets of such constraints. In this paper we present a collection of subroutines to deal with these tasks in a fast, reliable and systematic way, with examples for the leptonic sector.     

Invariant diagrams with data refinement

Invariant based programming is an approach where we start to construct a program by first identifying the basic situations (pre- and post-conditions as well as invariants) that could arise during the execution of the algorithm. These situations are identified before any code is written. After that, we identify the transitions between the situations, which will give us the flow of control in the program. Data refinement is a technique of building correct programs working on concrete data structures as refinements of more abstract programs working on abstract data types. We study in this paper data refinement for invariant based programs and we apply it to the construction of the classical Deutsch–Schorr–Waite graph marking algorithm. Our results are formalized and mechanically proved in the Isabelle/HOL theorem prover.